Overview
ISO/TS 21356-1:2021 - Nanotechnologies: Structural characterization of graphene - Part 1: Graphene from powders and dispersions defines a standardized sequence of measurement methods, sample-preparation routines and data analysis for structural characterization of graphene, bilayer graphene and graphene nanoplatelets (GNPs) originating from powders and liquid dispersions. Published jointly by ISO and IEC technical committees, the Technical Specification covers how to isolate individual flakes (typically by deposition on a substrate) and then determine key structural measurands needed for quality control, research and regulatory reporting.
Key topics
- Measurands specified: number of layers / thickness, lateral flake size, level of disorder, layer alignment, and specific surface area.
- Measurement sequence: recommends an efficient workflow (start with a rapid Raman check to detect graphitic material, then follow decision trees to choose detailed analyses).
- Characterization techniques included: Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and the BET (Brunauer–Emmett–Teller) method for surface area.
- Sample preparation & deposition: guidance on preparing dispersions of correct concentration and isolating flakes on substrates, with annexed protocols (e.g., silicon dioxide-on-silicon wafer prep).
- Data analysis & uncertainty: suggested protocols and annexes that cover lateral size and number-fraction calculations, TEM workflows, and BET analysis.
- Supporting material: flow-charts, decision trees and informative annexes that help implement repeatable, traceable measurements.
Applications
- Quality control and batch verification of commercial graphene powders and dispersions - ensuring suppliers’ claims about layer count, flake size and surface area are consistent.
- R&D and materials development for composites, flexible electronics, sensors, membrane filtration and energy storage where graphene structural properties affect performance.
- Regulatory and trade contexts that require standardized reporting and comparability across laboratories and suppliers.
- Instrument and method validation for labs implementing Raman, SEM, AFM, TEM or BET specifically for 2D carbon materials.
Who should use this standard
- Materials scientists, analytical laboratories and QA/QC teams working with graphene-containing powders or suspensions
- Graphene manufacturers and suppliers preparing product specifications
- Instrument vendors, test-lab managers and regulators seeking harmonized measurement protocols and reporting formats
Related standards
- ISO/TS 80004 series (nanotechnology vocabulary) - referenced normative documents, including ISO/TS 80004-13 (graphene & 2D materials) and ISO/TS 80004-6 (nano-object characterization)
- Other parts of the ISO/IEC 21356 series covering complementary characterization methods
Keywords: ISO TS 21356-1:2021, graphene characterization, powders and dispersions, Raman spectroscopy, AFM, SEM, TEM, BET, lateral flake size, number of layers, graphene nanoplatelets, sample preparation, measurement protocols.